Patent GB-1299769-A (GB)
Title: A process for the production of modified cationic emulsion polymers
Inventor: HONIG HANS LUDWIG
IPC: C08F283/00
Filed: 1970-10-16
Abstract: 1299769 Modified cationic emulsion polymers FARBENFABRIKEN BAYER AG 16 Oct 1970 [23 Oct 1969] 49312/70 Headings C3G and C3R A process for the production of stable aqueous polymer dispersions comprises subjecting at least one monomer having a polymerizable olefinic double bond to radical emulsion polymerization in the presence of a stable aqueous dispersion of a polyurethane of gel-like character containing cationic groups and having an average molecular weight in excess of 20,000. The cationic groups may be ammonium or sulphonium groups in which case the polyurethane dispersions may be made by reacting an active hydrogen compound with a molecular weight of 300 to 20,000, a polyisocyanate, and optionally a chain extender containing active hydrogen atoms together with 0À5-10% by weight of a trifunctional polyol and/or polyisocyanate, and/or 0À5-10% by weight of a crosslinking agent. The cross-linking agent may be a polyfunctional alkylating agent, an excess of polyisocyanate, or formaldehyde or a derivative thereof. The grafting monomer may be an α,#- unsaturated carboxylic acid or an ester, amide, imide, substituted amide or nitrile thereof, a vinyl ester, ether, ketone or amide, an aromatic or heterocyclic vinyl compound, a vinylidene compound, a divinyl compound, a monoolefin, a conjugated diolefin or an allyl compound. The polymerization is preferably carried out in the presence of a catalyst comprising an organic or inorganic peroxidic compound, in an amount 0À01-5% by weight, optionally together with a reducing agent. The reaction is preferably carried out at 0-150‹ C., more preferably at 30-100‹ C. Cationic or non-ionic emuisifiers may be added to the mixture, preferably in an amount up to 20% by weight. It is preferred to use from 5 to 95% by weight of cationic polyurethane to from 95% to 5% by weight of the monomers. The polyurethane dispersions usually have a solids content of 5 to 60% by weight. Specific polyurethane dispersions used are prepared by adding aqueous phosphoric acid to (I) the reaction product of a polythioether, prepared from thiodiglycol and 1,6-hexane diol, and tolylene diisocyanate reacted with a mixture of diethylene glycol, hexane-1,6-diol and N-methyl diethanolamine; (II) the reaction product of a polythioether, prepared from thiodiglycol and 1,6-hexane diol, and tolylene diisocyanate reacted with diethylene glycol, 1,4-butane diol and N-methyl diethanolamine; and (III) the reaction product of a polyester, obtained from adipic acid, phthalic acid and ethylene glycol, and tolylene diisocyanate reacted with dimethyl formamide and N-methyl diethanolamine. The specific examples refer to the following cationic polyurethane dispersion and monomer(s): (1) (I), (II) or (III) and a mixture of butyl acrylate and acrylonitrile, (3) (III) and styrene; (4) (III) and either a mixture of butyl acrylate and vinyl acetate or a mixture of butyl acrylate and vinylidene chloride; (5) and (6) (II) and vinyl chloride. Copending Specification 1,299,770 refers to the production of stable aqueous polymer dispersions based on anionic polyurethanes.